1. Field of the Invention
The present invention relates to an electronic device used in video applications and specifically to a filter performing a reduction of pulsed noise in video images using fuzzy logic.
The present invention also relates to a method for performing a reduction of the pulsed noise in video images using fuzzy logic.
2. Discussion of the Related Art
As is known, in the field of television signal processing a very serious problem is generally that of reducing the effects caused by the presence of noise without reducing the signal part which contains useful data.
A typical type of noise present in video signals is pulsed noise. The effects of pulsed noise are such as to change the gray level of a so-called image pixel so as to cause a peak of luminosity (positive or negative) to appear in a nearly homogeneous image region.
The presence of pulsed noise also causes nearly white or nearly black dots in the image which in the sequence of moving images cause a so-called snowy effect.
In scientific literature there are many examples of filters using fuzzy logic to perform a selection among the signal parts containing useful data and the signal part containing noise so as to filter out only the noise.
The fuzzy procedures used by these filters are described, for example, in the articles "Fuzzy Operators for Sharpening of Noisy Images" by F. Russo and G. Ramponi in Electronics Letters Vol. 28 No. 18, August 1992, and "Working on Image Data Using Fuzzy Rules" by F. Russo and G. Ramponi in Signal Processing IV Theories and Applications, Proceedings of EUSIPCO-92, Brussels, Belgium August 1992.
Although advantageous in some ways, the filters described by these articles exhibit very complex architectures.